Ttc for my 3rd baby

I've been TTC since I took my IUD out on the 1st of August... I haven't had a period since... I have notice that Ive been felling bloated, and gassy... last week I had spotting... I've had cramps... Small kind of pain on my right ovary... Small pain on my vagina... Just small pains that quickly go away... And lower back has been hurting sometimes... I have taken 3 pregnancy test from the brand EPT since September 19 and were all negative... Could this be pregnancy symptoms? Do I need to try other brand of pregnancy test? One more thing on August 4 I experienced bleeding till the 11th... I don't know if I should count that as a period because normally thats how long my periods last... Please need opinions!!